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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * Copyright (C) 2012-2013 Samsung Electronics Co., Ltd.4 */5 6#include <linux/slab.h>7#include <linux/compat.h>8#include <linux/cred.h>9#include <linux/buffer_head.h>10#include <linux/blkdev.h>11#include <linux/fsnotify.h>12#include <linux/security.h>13#include <linux/msdos_fs.h>14#include <linux/writeback.h>15 16#include "exfat_raw.h"17#include "exfat_fs.h"18 19static int exfat_cont_expand(struct inode *inode, loff_t size)20{21 int ret;22 unsigned int num_clusters, new_num_clusters, last_clu;23 struct exfat_inode_info *ei = EXFAT_I(inode);24 struct super_block *sb = inode->i_sb;25 struct exfat_sb_info *sbi = EXFAT_SB(sb);26 struct exfat_chain clu;27 28 ret = inode_newsize_ok(inode, size);29 if (ret)30 return ret;31 32 num_clusters = EXFAT_B_TO_CLU(exfat_ondisk_size(inode), sbi);33 new_num_clusters = EXFAT_B_TO_CLU_ROUND_UP(size, sbi);34 35 if (new_num_clusters == num_clusters)36 goto out;37 38 if (num_clusters) {39 exfat_chain_set(&clu, ei->start_clu, num_clusters, ei->flags);40 ret = exfat_find_last_cluster(sb, &clu, &last_clu);41 if (ret)42 return ret;43 44 clu.dir = last_clu + 1;45 } else {46 last_clu = EXFAT_EOF_CLUSTER;47 clu.dir = EXFAT_EOF_CLUSTER;48 }49 50 clu.size = 0;51 clu.flags = ei->flags;52 53 ret = exfat_alloc_cluster(inode, new_num_clusters - num_clusters,54 &clu, inode_needs_sync(inode));55 if (ret)56 return ret;57 58 /* Append new clusters to chain */59 if (num_clusters) {60 if (clu.flags != ei->flags)61 if (exfat_chain_cont_cluster(sb, ei->start_clu, num_clusters))62 goto free_clu;63 64 if (clu.flags == ALLOC_FAT_CHAIN)65 if (exfat_ent_set(sb, last_clu, clu.dir))66 goto free_clu;67 } else68 ei->start_clu = clu.dir;69 70 ei->flags = clu.flags;71 72out:73 inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode));74 /* Expanded range not zeroed, do not update valid_size */75 i_size_write(inode, size);76 77 inode->i_blocks = round_up(size, sbi->cluster_size) >> 9;78 mark_inode_dirty(inode);79 80 if (IS_SYNC(inode))81 return write_inode_now(inode, 1);82 83 return 0;84 85free_clu:86 exfat_free_cluster(inode, &clu);87 return -EIO;88}89 90static bool exfat_allow_set_time(struct mnt_idmap *idmap,91 struct exfat_sb_info *sbi, struct inode *inode)92{93 mode_t allow_utime = sbi->options.allow_utime;94 95 if (!vfsuid_eq_kuid(i_uid_into_vfsuid(idmap, inode),96 current_fsuid())) {97 if (vfsgid_in_group_p(i_gid_into_vfsgid(idmap, inode)))98 allow_utime >>= 3;99 if (allow_utime & MAY_WRITE)100 return true;101 }102 103 /* use a default check */104 return false;105}106 107static int exfat_sanitize_mode(const struct exfat_sb_info *sbi,108 struct inode *inode, umode_t *mode_ptr)109{110 mode_t i_mode, mask, perm;111 112 i_mode = inode->i_mode;113 114 mask = (S_ISREG(i_mode) || S_ISLNK(i_mode)) ?115 sbi->options.fs_fmask : sbi->options.fs_dmask;116 perm = *mode_ptr & ~(S_IFMT | mask);117 118 /* Of the r and x bits, all (subject to umask) must be present.*/119 if ((perm & 0555) != (i_mode & 0555))120 return -EPERM;121 122 if (exfat_mode_can_hold_ro(inode)) {123 /*124 * Of the w bits, either all (subject to umask) or none must125 * be present.126 */127 if ((perm & 0222) && ((perm & 0222) != (0222 & ~mask)))128 return -EPERM;129 } else {130 /*131 * If exfat_mode_can_hold_ro(inode) is false, can't change132 * w bits.133 */134 if ((perm & 0222) != (0222 & ~mask))135 return -EPERM;136 }137 138 *mode_ptr &= S_IFMT | perm;139 140 return 0;141}142 143/* resize the file length */144int __exfat_truncate(struct inode *inode)145{146 unsigned int num_clusters_new, num_clusters_phys;147 unsigned int last_clu = EXFAT_FREE_CLUSTER;148 struct exfat_chain clu;149 struct super_block *sb = inode->i_sb;150 struct exfat_sb_info *sbi = EXFAT_SB(sb);151 struct exfat_inode_info *ei = EXFAT_I(inode);152 153 /* check if the given file ID is opened */154 if (ei->type != TYPE_FILE && ei->type != TYPE_DIR)155 return -EPERM;156 157 exfat_set_volume_dirty(sb);158 159 num_clusters_new = EXFAT_B_TO_CLU_ROUND_UP(i_size_read(inode), sbi);160 num_clusters_phys = EXFAT_B_TO_CLU(exfat_ondisk_size(inode), sbi);161 162 exfat_chain_set(&clu, ei->start_clu, num_clusters_phys, ei->flags);163 164 if (i_size_read(inode) > 0) {165 /*166 * Truncate FAT chain num_clusters after the first cluster167 * num_clusters = min(new, phys);168 */169 unsigned int num_clusters =170 min(num_clusters_new, num_clusters_phys);171 172 /*173 * Follow FAT chain174 * (defensive coding - works fine even with corrupted FAT table175 */176 if (clu.flags == ALLOC_NO_FAT_CHAIN) {177 clu.dir += num_clusters;178 clu.size -= num_clusters;179 } else {180 while (num_clusters > 0) {181 last_clu = clu.dir;182 if (exfat_get_next_cluster(sb, &(clu.dir)))183 return -EIO;184 185 num_clusters--;186 clu.size--;187 }188 }189 } else {190 ei->flags = ALLOC_NO_FAT_CHAIN;191 ei->start_clu = EXFAT_EOF_CLUSTER;192 }193 194 if (i_size_read(inode) < ei->valid_size)195 ei->valid_size = i_size_read(inode);196 197 if (ei->type == TYPE_FILE)198 ei->attr |= EXFAT_ATTR_ARCHIVE;199 200 /*201 * update the directory entry202 *203 * If the directory entry is updated by mark_inode_dirty(), the204 * directory entry will be written after a writeback cycle of205 * updating the bitmap/FAT, which may result in clusters being206 * freed but referenced by the directory entry in the event of a207 * sudden power failure.208 * __exfat_write_inode() is called for directory entry, bitmap209 * and FAT to be written in a same writeback.210 */211 if (__exfat_write_inode(inode, inode_needs_sync(inode)))212 return -EIO;213 214 /* cut off from the FAT chain */215 if (ei->flags == ALLOC_FAT_CHAIN && last_clu != EXFAT_FREE_CLUSTER &&216 last_clu != EXFAT_EOF_CLUSTER) {217 if (exfat_ent_set(sb, last_clu, EXFAT_EOF_CLUSTER))218 return -EIO;219 }220 221 /* invalidate cache and free the clusters */222 /* clear exfat cache */223 exfat_cache_inval_inode(inode);224 225 /* hint information */226 ei->hint_bmap.off = EXFAT_EOF_CLUSTER;227 ei->hint_bmap.clu = EXFAT_EOF_CLUSTER;228 229 /* hint_stat will be used if this is directory. */230 ei->hint_stat.eidx = 0;231 ei->hint_stat.clu = ei->start_clu;232 ei->hint_femp.eidx = EXFAT_HINT_NONE;233 234 /* free the clusters */235 if (exfat_free_cluster(inode, &clu))236 return -EIO;237 238 return 0;239}240 241void exfat_truncate(struct inode *inode)242{243 struct super_block *sb = inode->i_sb;244 struct exfat_sb_info *sbi = EXFAT_SB(sb);245 struct exfat_inode_info *ei = EXFAT_I(inode);246 int err;247 248 mutex_lock(&sbi->s_lock);249 if (ei->start_clu == 0) {250 /*251 * Empty start_clu != ~0 (not allocated)252 */253 exfat_fs_error(sb, "tried to truncate zeroed cluster.");254 goto write_size;255 }256 257 err = __exfat_truncate(inode);258 if (err)259 goto write_size;260 261 inode->i_blocks = round_up(i_size_read(inode), sbi->cluster_size) >> 9;262write_size:263 mutex_unlock(&sbi->s_lock);264}265 266int exfat_getattr(struct mnt_idmap *idmap, const struct path *path,267 struct kstat *stat, unsigned int request_mask,268 unsigned int query_flags)269{270 struct inode *inode = d_backing_inode(path->dentry);271 struct exfat_inode_info *ei = EXFAT_I(inode);272 273 generic_fillattr(idmap, request_mask, inode, stat);274 exfat_truncate_atime(&stat->atime);275 stat->result_mask |= STATX_BTIME;276 stat->btime.tv_sec = ei->i_crtime.tv_sec;277 stat->btime.tv_nsec = ei->i_crtime.tv_nsec;278 stat->blksize = EXFAT_SB(inode->i_sb)->cluster_size;279 return 0;280}281 282int exfat_setattr(struct mnt_idmap *idmap, struct dentry *dentry,283 struct iattr *attr)284{285 struct exfat_sb_info *sbi = EXFAT_SB(dentry->d_sb);286 struct inode *inode = dentry->d_inode;287 unsigned int ia_valid;288 int error;289 290 if (unlikely(exfat_forced_shutdown(inode->i_sb)))291 return -EIO;292 293 if ((attr->ia_valid & ATTR_SIZE) &&294 attr->ia_size > i_size_read(inode)) {295 error = exfat_cont_expand(inode, attr->ia_size);296 if (error || attr->ia_valid == ATTR_SIZE)297 return error;298 attr->ia_valid &= ~ATTR_SIZE;299 }300 301 /* Check for setting the inode time. */302 ia_valid = attr->ia_valid;303 if ((ia_valid & (ATTR_MTIME_SET | ATTR_ATIME_SET | ATTR_TIMES_SET)) &&304 exfat_allow_set_time(idmap, sbi, inode)) {305 attr->ia_valid &= ~(ATTR_MTIME_SET | ATTR_ATIME_SET |306 ATTR_TIMES_SET);307 }308 309 error = setattr_prepare(idmap, dentry, attr);310 attr->ia_valid = ia_valid;311 if (error)312 goto out;313 314 if (((attr->ia_valid & ATTR_UID) &&315 (!uid_eq(from_vfsuid(idmap, i_user_ns(inode), attr->ia_vfsuid),316 sbi->options.fs_uid))) ||317 ((attr->ia_valid & ATTR_GID) &&318 (!gid_eq(from_vfsgid(idmap, i_user_ns(inode), attr->ia_vfsgid),319 sbi->options.fs_gid))) ||320 ((attr->ia_valid & ATTR_MODE) &&321 (attr->ia_mode & ~(S_IFREG | S_IFLNK | S_IFDIR | 0777)))) {322 error = -EPERM;323 goto out;324 }325 326 /*327 * We don't return -EPERM here. Yes, strange, but this is too328 * old behavior.329 */330 if (attr->ia_valid & ATTR_MODE) {331 if (exfat_sanitize_mode(sbi, inode, &attr->ia_mode) < 0)332 attr->ia_valid &= ~ATTR_MODE;333 }334 335 if (attr->ia_valid & ATTR_SIZE)336 inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode));337 338 setattr_copy(idmap, inode, attr);339 exfat_truncate_inode_atime(inode);340 341 if (attr->ia_valid & ATTR_SIZE) {342 error = exfat_block_truncate_page(inode, attr->ia_size);343 if (error)344 goto out;345 346 down_write(&EXFAT_I(inode)->truncate_lock);347 truncate_setsize(inode, attr->ia_size);348 349 /*350 * __exfat_write_inode() is called from exfat_truncate(), inode351 * is already written by it, so mark_inode_dirty() is unneeded.352 */353 exfat_truncate(inode);354 up_write(&EXFAT_I(inode)->truncate_lock);355 } else356 mark_inode_dirty(inode);357 358out:359 return error;360}361 362/*363 * modified ioctls from fat/file.c by Welmer Almesberger364 */365static int exfat_ioctl_get_attributes(struct inode *inode, u32 __user *user_attr)366{367 u32 attr;368 369 inode_lock_shared(inode);370 attr = exfat_make_attr(inode);371 inode_unlock_shared(inode);372 373 return put_user(attr, user_attr);374}375 376static int exfat_ioctl_set_attributes(struct file *file, u32 __user *user_attr)377{378 struct inode *inode = file_inode(file);379 struct exfat_sb_info *sbi = EXFAT_SB(inode->i_sb);380 int is_dir = S_ISDIR(inode->i_mode);381 u32 attr, oldattr;382 struct iattr ia;383 int err;384 385 err = get_user(attr, user_attr);386 if (err)387 goto out;388 389 err = mnt_want_write_file(file);390 if (err)391 goto out;392 inode_lock(inode);393 394 oldattr = exfat_make_attr(inode);395 396 /*397 * Mask attributes so we don't set reserved fields.398 */399 attr &= (EXFAT_ATTR_READONLY | EXFAT_ATTR_HIDDEN | EXFAT_ATTR_SYSTEM |400 EXFAT_ATTR_ARCHIVE);401 attr |= (is_dir ? EXFAT_ATTR_SUBDIR : 0);402 403 /* Equivalent to a chmod() */404 ia.ia_valid = ATTR_MODE | ATTR_CTIME;405 ia.ia_ctime = current_time(inode);406 if (is_dir)407 ia.ia_mode = exfat_make_mode(sbi, attr, 0777);408 else409 ia.ia_mode = exfat_make_mode(sbi, attr, 0666 | (inode->i_mode & 0111));410 411 /* The root directory has no attributes */412 if (inode->i_ino == EXFAT_ROOT_INO && attr != EXFAT_ATTR_SUBDIR) {413 err = -EINVAL;414 goto out_unlock_inode;415 }416 417 if (((attr | oldattr) & EXFAT_ATTR_SYSTEM) &&418 !capable(CAP_LINUX_IMMUTABLE)) {419 err = -EPERM;420 goto out_unlock_inode;421 }422 423 /*424 * The security check is questionable... We single425 * out the RO attribute for checking by the security426 * module, just because it maps to a file mode.427 */428 err = security_inode_setattr(file_mnt_idmap(file),429 file->f_path.dentry, &ia);430 if (err)431 goto out_unlock_inode;432 433 /* This MUST be done before doing anything irreversible... */434 err = exfat_setattr(file_mnt_idmap(file), file->f_path.dentry, &ia);435 if (err)436 goto out_unlock_inode;437 438 fsnotify_change(file->f_path.dentry, ia.ia_valid);439 440 exfat_save_attr(inode, attr);441 mark_inode_dirty(inode);442out_unlock_inode:443 inode_unlock(inode);444 mnt_drop_write_file(file);445out:446 return err;447}448 449static int exfat_ioctl_fitrim(struct inode *inode, unsigned long arg)450{451 struct fstrim_range range;452 int ret = 0;453 454 if (!capable(CAP_SYS_ADMIN))455 return -EPERM;456 457 if (!bdev_max_discard_sectors(inode->i_sb->s_bdev))458 return -EOPNOTSUPP;459 460 if (copy_from_user(&range, (struct fstrim_range __user *)arg, sizeof(range)))461 return -EFAULT;462 463 range.minlen = max_t(unsigned int, range.minlen,464 bdev_discard_granularity(inode->i_sb->s_bdev));465 466 ret = exfat_trim_fs(inode, &range);467 if (ret < 0)468 return ret;469 470 if (copy_to_user((struct fstrim_range __user *)arg, &range, sizeof(range)))471 return -EFAULT;472 473 return 0;474}475 476static int exfat_ioctl_shutdown(struct super_block *sb, unsigned long arg)477{478 u32 flags;479 480 if (!capable(CAP_SYS_ADMIN))481 return -EPERM;482 483 if (get_user(flags, (__u32 __user *)arg))484 return -EFAULT;485 486 return exfat_force_shutdown(sb, flags);487}488 489long exfat_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)490{491 struct inode *inode = file_inode(filp);492 u32 __user *user_attr = (u32 __user *)arg;493 494 switch (cmd) {495 case FAT_IOCTL_GET_ATTRIBUTES:496 return exfat_ioctl_get_attributes(inode, user_attr);497 case FAT_IOCTL_SET_ATTRIBUTES:498 return exfat_ioctl_set_attributes(filp, user_attr);499 case EXFAT_IOC_SHUTDOWN:500 return exfat_ioctl_shutdown(inode->i_sb, arg);501 case FITRIM:502 return exfat_ioctl_fitrim(inode, arg);503 default:504 return -ENOTTY;505 }506}507 508#ifdef CONFIG_COMPAT509long exfat_compat_ioctl(struct file *filp, unsigned int cmd,510 unsigned long arg)511{512 return exfat_ioctl(filp, cmd, (unsigned long)compat_ptr(arg));513}514#endif515 516int exfat_file_fsync(struct file *filp, loff_t start, loff_t end, int datasync)517{518 struct inode *inode = filp->f_mapping->host;519 int err;520 521 if (unlikely(exfat_forced_shutdown(inode->i_sb)))522 return -EIO;523 524 err = __generic_file_fsync(filp, start, end, datasync);525 if (err)526 return err;527 528 err = sync_blockdev(inode->i_sb->s_bdev);529 if (err)530 return err;531 532 return blkdev_issue_flush(inode->i_sb->s_bdev);533}534 535static int exfat_extend_valid_size(struct file *file, loff_t new_valid_size)536{537 int err;538 loff_t pos;539 struct inode *inode = file_inode(file);540 struct exfat_inode_info *ei = EXFAT_I(inode);541 struct address_space *mapping = inode->i_mapping;542 const struct address_space_operations *ops = mapping->a_ops;543 544 pos = ei->valid_size;545 while (pos < new_valid_size) {546 u32 len;547 struct folio *folio;548 549 len = PAGE_SIZE - (pos & (PAGE_SIZE - 1));550 if (pos + len > new_valid_size)551 len = new_valid_size - pos;552 553 err = ops->write_begin(file, mapping, pos, len, &folio, NULL);554 if (err)555 goto out;556 557 err = ops->write_end(file, mapping, pos, len, len, folio, NULL);558 if (err < 0)559 goto out;560 pos += len;561 562 balance_dirty_pages_ratelimited(mapping);563 cond_resched();564 }565 566out:567 return err;568}569 570static ssize_t exfat_file_write_iter(struct kiocb *iocb, struct iov_iter *iter)571{572 ssize_t ret;573 struct file *file = iocb->ki_filp;574 struct inode *inode = file_inode(file);575 struct exfat_inode_info *ei = EXFAT_I(inode);576 loff_t pos = iocb->ki_pos;577 loff_t valid_size;578 579 inode_lock(inode);580 581 valid_size = ei->valid_size;582 583 ret = generic_write_checks(iocb, iter);584 if (ret < 0)585 goto unlock;586 587 if (pos > valid_size) {588 ret = exfat_extend_valid_size(file, pos);589 if (ret < 0 && ret != -ENOSPC) {590 exfat_err(inode->i_sb,591 "write: fail to zero from %llu to %llu(%zd)",592 valid_size, pos, ret);593 }594 if (ret < 0)595 goto unlock;596 }597 598 ret = __generic_file_write_iter(iocb, iter);599 if (ret < 0)600 goto unlock;601 602 inode_unlock(inode);603 604 if (pos > valid_size)605 pos = valid_size;606 607 if (iocb_is_dsync(iocb) && iocb->ki_pos > pos) {608 ssize_t err = vfs_fsync_range(file, pos, iocb->ki_pos - 1,609 iocb->ki_flags & IOCB_SYNC);610 if (err < 0)611 return err;612 }613 614 return ret;615 616unlock:617 inode_unlock(inode);618 619 return ret;620}621 622static vm_fault_t exfat_page_mkwrite(struct vm_fault *vmf)623{624 int err;625 struct vm_area_struct *vma = vmf->vma;626 struct file *file = vma->vm_file;627 struct inode *inode = file_inode(file);628 struct exfat_inode_info *ei = EXFAT_I(inode);629 loff_t start, end;630 631 if (!inode_trylock(inode))632 return VM_FAULT_RETRY;633 634 start = ((loff_t)vma->vm_pgoff << PAGE_SHIFT);635 end = min_t(loff_t, i_size_read(inode),636 start + vma->vm_end - vma->vm_start);637 638 if (ei->valid_size < end) {639 err = exfat_extend_valid_size(file, end);640 if (err < 0) {641 inode_unlock(inode);642 return vmf_fs_error(err);643 }644 }645 646 inode_unlock(inode);647 648 return filemap_page_mkwrite(vmf);649}650 651static const struct vm_operations_struct exfat_file_vm_ops = {652 .fault = filemap_fault,653 .map_pages = filemap_map_pages,654 .page_mkwrite = exfat_page_mkwrite,655};656 657static int exfat_file_mmap(struct file *file, struct vm_area_struct *vma)658{659 file_accessed(file);660 vma->vm_ops = &exfat_file_vm_ops;661 return 0;662}663 664const struct file_operations exfat_file_operations = {665 .llseek = generic_file_llseek,666 .read_iter = generic_file_read_iter,667 .write_iter = exfat_file_write_iter,668 .unlocked_ioctl = exfat_ioctl,669#ifdef CONFIG_COMPAT670 .compat_ioctl = exfat_compat_ioctl,671#endif672 .mmap = exfat_file_mmap,673 .fsync = exfat_file_fsync,674 .splice_read = filemap_splice_read,675 .splice_write = iter_file_splice_write,676};677 678const struct inode_operations exfat_file_inode_operations = {679 .setattr = exfat_setattr,680 .getattr = exfat_getattr,681};682